Chemical composition of solutions in macro- and micropores in the upper horizons of soils in the Central Forest State Biosphere Reserve

The average concentrations of Al, Si, Fe, Mn, Pb, Ni, V, Ba, and other elements were 1.5–3.5 times lower (in some cases, up to 60 times) in the macropores than in the micropores. The regularities found agreed with the rules of selective absorption of ions and their capability for the formation of complexes with the components of the soil solids. The behavior of Fe and Mn can be explained by the differences in the redox conditions in the pores of different sizes. The degree of the relationships between the soil solution and the solid phase of the matrix in the macro- and micropores differed by several orders of magnitude (within a pF range up to 4). This fact determined the different mobilization of the elements in the solutions of the macro- and micropores. The reserves of the elements were proportional not only to their concentrations but also to the amount of solution in the appropriate pores.